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/* |
FUNCTION |
<<strtol>>---string to long |
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INDEX |
strtol |
INDEX |
_strtol_r |
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ANSI_SYNOPSIS |
#include <stdlib.h> |
long strtol(const char *<[s]>, char **<[ptr]>,int <[base]>); |
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long _strtol_r(void *<[reent]>, |
const char *<[s]>, char **<[ptr]>,int <[base]>); |
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TRAD_SYNOPSIS |
#include <stdlib.h> |
long strtol (<[s]>, <[ptr]>, <[base]>) |
char *<[s]>; |
char **<[ptr]>; |
int <[base]>; |
|
long _strtol_r (<[reent]>, <[s]>, <[ptr]>, <[base]>) |
char *<[reent]>; |
char *<[s]>; |
char **<[ptr]>; |
int <[base]>; |
|
DESCRIPTION |
The function <<strtol>> converts the string <<*<[s]>>> to |
a <<long>>. First, it breaks down the string into three parts: |
leading whitespace, which is ignored; a subject string consisting |
of characters resembling an integer in the radix specified by <[base]>; |
and a trailing portion consisting of zero or more unparseable characters, |
and always including the terminating null character. Then, it attempts |
to convert the subject string into a <<long>> and returns the |
result. |
|
If the value of <[base]> is 0, the subject string is expected to look |
like a normal C integer constant: an optional sign, a possible `<<0x>>' |
indicating a hexadecimal base, and a number. If <[base]> is between |
2 and 36, the expected form of the subject is a sequence of letters |
and digits representing an integer in the radix specified by <[base]>, |
with an optional plus or minus sign. The letters <<a>>--<<z>> (or, |
equivalently, <<A>>--<<Z>>) are used to signify values from 10 to 35; |
only letters whose ascribed values are less than <[base]> are |
permitted. If <[base]> is 16, a leading <<0x>> is permitted. |
|
The subject sequence is the longest initial sequence of the input |
string that has the expected form, starting with the first |
non-whitespace character. If the string is empty or consists entirely |
of whitespace, or if the first non-whitespace character is not a |
permissible letter or digit, the subject string is empty. |
|
If the subject string is acceptable, and the value of <[base]> is zero, |
<<strtol>> attempts to determine the radix from the input string. A |
string with a leading <<0x>> is treated as a hexadecimal value; a string with |
a leading 0 and no <<x>> is treated as octal; all other strings are |
treated as decimal. If <[base]> is between 2 and 36, it is used as the |
conversion radix, as described above. If the subject string begins with |
a minus sign, the value is negated. Finally, a pointer to the first |
character past the converted subject string is stored in <[ptr]>, if |
<[ptr]> is not <<NULL>>. |
|
If the subject string is empty (or not in acceptable form), no conversion |
is performed and the value of <[s]> is stored in <[ptr]> (if <[ptr]> is |
not <<NULL>>). |
|
The alternate function <<_strtol_r>> is a reentrant version. The |
extra argument <[reent]> is a pointer to a reentrancy structure. |
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RETURNS |
<<strtol>> returns the converted value, if any. If no conversion was |
made, 0 is returned. |
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<<strtol>> returns <<LONG_MAX>> or <<LONG_MIN>> if the magnitude of |
the converted value is too large, and sets <<errno>> to <<ERANGE>>. |
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PORTABILITY |
<<strtol>> is ANSI. |
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No supporting OS subroutines are required. |
*/ |
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/*- |
* Copyright (c) 1990 The Regents of the University of California. |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* 1. Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* 2. Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* 3. All advertising materials mentioning features or use of this software |
* must display the following acknowledgement: |
* This product includes software developed by the University of |
* California, Berkeley and its contributors. |
* 4. Neither the name of the University nor the names of its contributors |
* may be used to endorse or promote products derived from this software |
* without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
* SUCH DAMAGE. |
*/ |
|
|
#include <_ansi.h> |
#include <limits.h> |
#include <ctype.h> |
#include <errno.h> |
#include <stdlib.h> |
#include <reent.h> |
|
/* |
* Convert a string to a long integer. |
* |
* Ignores `locale' stuff. Assumes that the upper and lower case |
* alphabets and digits are each contiguous. |
*/ |
long |
_DEFUN (_strtol_r, (rptr, nptr, endptr, base), |
struct _reent *rptr _AND |
_CONST char *nptr _AND |
char **endptr _AND |
int base) |
{ |
register const unsigned char *s = (const unsigned char *)nptr; |
register unsigned long acc; |
register int c; |
register unsigned long cutoff; |
register int neg = 0, any, cutlim; |
|
/* |
* Skip white space and pick up leading +/- sign if any. |
* If base is 0, allow 0x for hex and 0 for octal, else |
* assume decimal; if base is already 16, allow 0x. |
*/ |
do { |
c = *s++; |
} while (isspace(c)); |
if (c == '-') { |
neg = 1; |
c = *s++; |
} else if (c == '+') |
c = *s++; |
if ((base == 0 || base == 16) && |
c == '0' && (*s == 'x' || *s == 'X')) { |
c = s[1]; |
s += 2; |
base = 16; |
} |
if (base == 0) |
base = c == '0' ? 8 : 10; |
|
/* |
* Compute the cutoff value between legal numbers and illegal |
* numbers. That is the largest legal value, divided by the |
* base. An input number that is greater than this value, if |
* followed by a legal input character, is too big. One that |
* is equal to this value may be valid or not; the limit |
* between valid and invalid numbers is then based on the last |
* digit. For instance, if the range for longs is |
* [-2147483648..2147483647] and the input base is 10, |
* cutoff will be set to 214748364 and cutlim to either |
* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated |
* a value > 214748364, or equal but the next digit is > 7 (or 8), |
* the number is too big, and we will return a range error. |
* |
* Set any if any `digits' consumed; make it negative to indicate |
* overflow. |
*/ |
cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX; |
cutlim = cutoff % (unsigned long)base; |
cutoff /= (unsigned long)base; |
for (acc = 0, any = 0;; c = *s++) { |
if (isdigit(c)) |
c -= '0'; |
else if (isalpha(c)) |
c -= isupper(c) ? 'A' - 10 : 'a' - 10; |
else |
break; |
if (c >= base) |
break; |
if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim)) |
any = -1; |
else { |
any = 1; |
acc *= base; |
acc += c; |
} |
} |
if (any < 0) { |
acc = neg ? LONG_MIN : LONG_MAX; |
rptr->_errno = ERANGE; |
} else if (neg) |
acc = -acc; |
if (endptr != 0) |
*endptr = (char *) (any ? (char *)s - 1 : nptr); |
return (acc); |
} |
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#ifndef _REENT_ONLY |
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long |
_DEFUN (strtol, (s, ptr, base), |
_CONST char *s _AND |
char **ptr _AND |
int base) |
{ |
return _strtol_r (_REENT, s, ptr, base); |
} |
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#endif |